Why Are U.S. Theaters Battling Disney Over “Iron Man 3″?

In the midst of a nationwide slump in ticket sales, AMC (PINK: ACFL) and Regal Theaters (NYSE:RGC) are going to battle with Disney (NYSE:DIS) over the highly anticipated ”Iron Man 3″ release. Though the blockbuster was expected to kick off the summer season in two weeks, the two top theater chains have stopped selling advance tickets until they resolve an ongoing revenue-sharing dispute.

At the heart of the dispute is an aggressive stance by Disney on the numbers it will receive for “Iron Man 3,” expected to have a huge opening weekend and follow with earnings that could reach above $400 million. Deadline Hollywood reports that Disney has not negotiated a new contract with the top theaters in years and considers itself on the short end of present and future releases (including the next “Star Wars” installments).

Yet AMC and Regal, which together control over 30 percent of U.S. theaters, have not blinked in the standoff. As with any labor negotiations, their strength comes in numbers. On Wednesday, AMC announced it would stop advance ticket sales for the newest “Iron Man” picture starring Robert Downey, Jr. because of Disney’s hard-line stance on the revenue share. AMC CEO Gerry Lopez had some choice words for Disney in a report by the L.A. Times…